Nitrite oxidoreductase(NXR) is the key enzyme responsible for the oxidation of NO2-to NO3-in nitrite-oxidizing bacteria.Since NXR is a dissoluble enzyme,located at the inner side of the membranes of cells,its function is dependent on the electron transfer chain related to membranes.This paper reviews the advances in study on NXR,including the structure,catalysis mechanism and the impact of different factors.New techniques applied in recent studies and research prospects are also presented.

Objective To investigate the resistant mechanism of imipenem-resistant K. pneumoniae.Methods The minimal inhibitive concentrations (MICs) of the antimicrobial agents were determined by Etest.Isoelectric focusing electrophoresis (IEF),plasmid extraction,conjugation, transformation,PCR amplification,cloning and sequencing were carried out for analyzing the encoding gene of ?-1actamases.Results Three kinds of ?-1actamases were detected with pIs of 7.2,6.7,and 5.4.in a clinical strain of K.pneumoniae.These ?-1actamases were TEM-I (pI,5.4),SHV-12 (pI,8.2) and KPC-2 ( pI,6.7 ) confirmed by sequencing of the PCR products.Only one band of ?-1actamase with pI 6.7 was displayed in the transformant.A 1500 bp segment,which contained the KPC-2 gene confirmed by nucleotide sequence analysis,was cloned from a 60 000 bp plasmid of the transformant.Conclusion The strain of K.pneumoniae resistant to imipenem produces a plasmid-mediated carbapenemase KPC-2 which belongs to Bush group 2f,class A ?-1actamase.

Objective: To investigate the effect of taurine on learning and memory impairment, cytokines secretion in rats intrahippocampally injected with ?-amyloid (A?) 1-40. Methods: SD rats were randomly divided into control group, A? injected group, taurine (0.3g/kg?d, 0.6g/kg?d) groups. The rats were fed with taurine for 7 days, and then subjected to bilateral intrahippocampus injection of A?1-40 or vehicle. Two weeks later, all rats performed Morris water maze test. The contents of IL-6, TNF-? were checked by way of radio-immunity assay for hippocampus samples. Results: Compared with A?model group, the escape latency and distance were significantly reduced in taurine (0.6g/kg?d) group; the ratio of swimming distance in the target quadrant to that in the whole pool of the probe trial; the content of cytokines of IL-6 and TNF-?in hippocampus were reduced significantly. Conclusion: Taurine can effectively attenuate the cognitive dysfunction caused by A?1-40 in rats. The reduced cytokines content in hippocampus might contribute to this effect.

Objective:To observe the effect of liver-soothing and mind-regulating acupuncture method on the resting-state electroencephalography (EEG) in rats with post-traumatic stress disorder (PTSD),and to provide evidence for the effect mechanism study and clinical application of acupuncture intervention for PTSD.Methods:Sixty Sprague-Dawley (SD) rats were randomly divided into a blank control group,a model group,a grasping group,a paroxetine group and an acupuncture group,with 12 rats in each group.Except for rats in the blank control group,rats in the other groups were subjected to preparing the PTSD models using 'incarceration plus electric shock' method.After interventions,changes in rat behavior of each group were observed;changes in resting-state EEG were collected and analyzed with multichannel EEG acquisition and analysis system,and image analysis and statistical processing were performed.Results:Compared with the blank control group,the average escape latency in the model group was significantly longer (P＜0.05),and the times of crossing the platform and the effective areas were all significantly reduced (P＜0.01).Compared with the grasping group,the average escape latencies in the paroxetine group and acupuncture group were significantly shortened (P＜0.05),and the times of crossing the platform and the effective areas were all significantly increased (P＜0.05).There were no significant differences in the average escape latency,the times of crossing the platform and the effective areas between the acupuncture group and paroxetine group (all P＞0.05).Compared with the blank control group,the α-wave power spectrum value in the model group was significantly decreased,and the power spectrum values of β-wave,δ-wave and a-wave were significantly increased (all P＜0.01);compared with the grasping group,α-wave power spectrum values in the paroxetine group and acupuncture group were significantly increased (both P＜0.01),and the power spectrum values of β-wave,δ-wave and a-wave were decreased significantly (all P＜0.01).The power spectrum values of α-wave,β-wave,δ-wave and (e)-wave of rats in the acupuncture group were not significantly different from those in the paroxetine group (all P＞0.05).Conclusion:Liver-soothing and mind-regulating acupuncture method can significantly improve the abnormal EEG activity in PTSD rats,which may be one mechanism of liver-soothing and mind-regulating acupuncture method in effectively affecting the brain function in PTSD rats.

Objective To compare effection of two kinds of bowel preparation for enteroscopy in aged patients. Methods 100 patients who would receive enteroseopy were divided into two groups. 50 cases in each group. Patients in experimental group received colon dialysis, patients in control group received oral medication. Observed the effectiveness of two kind of bowel preparations and adverse reaction. Results The effectiveness of colon dialysis was superior to oral medication(P <0. 05) ,there was no significant deviation the adverse reaction of two groups. Conclusions Colon dialysis is a suitable method in bowel preparation for enteroscopy in aged patients.

Objective To investigate the expression of peroxisome proliferator-activated receptor (PPAR?)in lupus nephritis(LN)patients and the possible mechanisms of PPAR?in the pathogenesis of LN. Method PPAR?expression was examined in 21 LN patients and 5 normal kidney biopsy specimens by im- munohistochemical method.The relationship between PPAR?expression and renal pathologic changes was an- alyzed.Results Glomerular and tubular positive staining of PPAR?in LN patients was markedly up-regulated compared with that in normal kidney specimens.The distribution and expression of PPAR?in classⅣwas sig- nificantly increased compared with that in classⅤandⅡ.The relevance assay showed that there was positive relationship between active index and glomerular PPAR?immunohistochemistry staining cell numbers(r=0.94, P＜0.01 ).Conclusion This study demonstrates in vivo that PPAR?expression is increased in active LN pa- tients with pathological active inflammation.These data suggest that the increase of PPAR?expression in renal cells may play an important role in the pathogenesis of LN.

OBJECTIVETo establish and evaluate chronic heart failure (CHF) rat model of Xin-qi deficiency complicated blood stasis and edema syndrome (XQD-BSES).

METHODSTotally 40 SD rats were randomly divided into the normal control group (Control), the propylthiouracil (PTU) group, the adriamycin (ADR), and the ADR + PTU group. Normal saline was used as equivalent solvent of each group. Rats in the Control group were intragastrically and intraperitoneally injected with normal saline. Rats in the PTU group were intragastrically injected with PTU suspension and intraperitoneally injected with normal saline. Rats in the ADR group were intragastrically injected with ADR solution and intraperitoneally injected with normal saline. And rats in the ADR + PTU group were intragastrically injected with PTU suspension and intraperitoneally injected with ADR solution. The dose of PTU was 0.2% of daily forage weight, once daily. The dose of ADR was 3.5 mg/kg, once per week. The modeling lasted for 6 weeks. Left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), brain natriuretic peptide (BNP), heart rate (HR), respiratory rate (RR), urine output, ear temperature, exhaustive swimming test (EST), Tri-iodothyronine (T3), tetra-iodothyronine(T4), thyroid stimulating hormone (TSH) as well as heart, lung, liver weight indices and their pathological sections were integrated and compared.

RESULTSCompared with the Control group, LVEF, LVFS, BNP, HR, RR, heart, lung, liver weight indices, urine output, ear temperature, EST, and T3, T4, and TSH changed significantly in the ADR group, the PTU group, and the ADR + PTU group with statistical significance (P < 0.05), and pathological changes of heart failure occurred in pathological sections of heart, lung, and liver. Compared with the ADR group, LVEF, LVFS, BNP, and lung, liver weight indices, urine output, ear temperature, T3, T4, and TSH changed significantly in the ADR + PTU group with statistical significance (P < 0.05), and pathological changes of heart failure were more serious in pathological sections of heart, lung, and liver. Compared with the PTU group, LVEF, LVFS, BNP, HR, RR, urine output, EST, T4, heart and lung weight indices changed significantly in the ADR + PTU group with statistical significance (P < 0.05), and pathological changes of heart failure were quite serious in pathological sections of heart, lung, and liver.

CONCLUSIONADR + PTU was an appropriate method to establish CHF rat model of XQD-BSES.

Animals ; Edema ; Heart Failure ; diagnosis ; Heart Ventricles ; Humans ; Judgment ; Models, Animal ; Qi ; Rats ; Ventricular Function, Left

OBJECTIVETo establish a rapid specific method to identify the single-nucleotide polymorphisms (SNPs) of HBV polymerase gene region which are the methionine residue of the conserved YMDD motif.

METHODSTwo specific primers were designed to amplify interested gene region involved in SNPs which were also used as HBV DNA identification. Specific primers of SNaPshot were designed to detect 741A-G (YVDD), 743G-T (YIDD). The different fluorescent dye labeled ddNTP was used to further extend the strand of PCR product and was detected by ABI PRISM 310 Genetic Analyzer. Sera from 13 patients with chronic hepatitis B after lamivudine treatment were analyzed.

RESULTSAside from mutation of YMDD, there were mutations of 514C-A, 523C-A, 562T-A, 667C-A. The 13 samples were simultaneously tested with SNaPshot and DNA sequencing, the same results were obtained. The method of SNaPshot showed high specificity.

CONCLUSIONMutation of YMDD results in the changes of ATG codon, and there are new ATG codon in the upper strand of YMDD. SNaPshot technique is rapid, specific and accurate for the SNPs monitoring of HBV DNA mutation during lamivudine therapy. Two samples were determined by SnaPshot technique, identifying the co-existence of the mixed wild type and mutant type HBV infection.

Antiviral Agents ; therapeutic use ; Base Sequence ; DNA, Viral ; blood ; genetics ; Drug Resistance, Viral ; Gene Products, pol ; genetics ; Hepatitis B ; blood ; drug therapy ; virology ; Humans ; Lamivudine ; therapeutic use ; Polymorphism, Single Nucleotide ; Sequence Analysis, DNA

OBJECTIVETo study the effect of a low level of galacto-oligosaccharides (GOS) on intestinal bifidobacteria and lactobacilli, and fermentation characteristics in term infants by comparing with human milk and a standard infant formula without GOS.

METHODSA total of 371 term infants from four hospitals of China were enrolled. The infants started with breast feeding. After 1-2 weeks, some of the infants were changed to feeding with formula milk and then were randomly assigned to two formula-feeding groups: with or without GOS supplementation (2.4 g/L). Growth, stool characteristics, and side effects were recorded in a 3-month-follow-up. Faecal samples were collected for analysis of intestinal bacteria (culture technique), acetic acid (gas chromatography) and pH (indicator strip) at postnatal 3 months.

RESULTSCompared with the formula-feeding group without GOS, the contents of bifidobacteria, lactobacilli and acetic acid and stool frequency increased, and faecal pH decreased significantly in the GOS-formula-feeding and the human milk group. There were no significant differences between the GOS-formula-feeding and the human milk groups. Supplementation with GOS did not lead to an increase in the incidence of crying, regurgitation and vomiting.

CONCLUSIONSA supplementation of low levels of GOS in infant formula seemed to improve stool frequency, decrease faecal pH, and stimulate intestinal bifidobacteria and lactobacilli up to levels as found in breast-fed infants.

Bifidobacterium ; isolation & purification ; Dietary Supplements ; Galactose ; administration & dosage ; Humans ; Hydrogen-Ion Concentration ; Infant Formula ; Infant, Newborn ; Intestines ; microbiology ; Lactobacillus ; isolation & purification ; Oligosaccharides ; administration & dosage

OBJECTIVETo study the rehabilitation effects ergometry on COPD patients.

METHODSThirty COPD out-patients in our Hospital were randomly divided into 2 groups. Rehabilitation group, 15 patients, performed leg ergometry exercise of 80% peak Watt x 30min/d x 3d/w x 12w. Another 15 patients were control group without exercise. All patients received conventional therapy. Pulmonary function testing (PFT), cardiopulmonary exercise testing (CPET), arterial blood gas analysis (ABG), Borg and CAT sores were done at both baseline and 12 w.

RESULTSThere was no statistically difference in lung function testing, blood gas analysis and cardiopulmonary exercise test when pre- exercises between 2 sub-groups. The IC, peak VO2 and peak, W of rehabilitation group significantly increased (P < 0.05); and Borg and CAT.scores significantly decreased (P < 0.05) from baseline; and other PFT and ABG did not change (P > 0.05). While there was no difference in control group (P > 0.05).

CONCLUSIONLeg submaximal ergometry rehabilitation improves health condition and ameliorate dyspnea symptoms in COPD patients.

Blood Gas Analysis ; Dyspnea ; therapy ; Exercise Test ; Exercise Therapy ; Humans ; Pulmonary Disease, Chronic Obstructive ; therapy ; Respiratory Function Tests